1. Field of the Invention
The present invention generally relates to a manually operable sweeping-type printing apparatus, and, more particularly, to a manually operable printer apparatus where data previously stored in a memory is printed out on a printing medium, while manually sweeping the printer apparatus over a printing medium.
2. Description of the Related Art
Various types of manually operable sweeping-type printers are known in the art, for example, U.S. Pat. No. 3,767,020 issued to Rowe on Oct. 23, 1973, entitled "MANUALLY POSITIONABLE AUTOMATIC PRINTER". In the manually movable housing of this known printer, there are provided a printer head, an ink ribbon, rotatable rollers in contact with the printing medium, and a timing-signal generating unit for producing a timing signal in accordance with a travel distance over which the printer housing has been moved. A control unit and memory unit connected with each other by means of a connection cord are arranged in the printer housing.
While the printer housing is manually moved over the printing medium, the information previously stored in the memory unit is printed out on the printing medium. Since the printing control is performed based upon the actual movement of the housing of the manually sweepable automatic printer, an operator should stop moving the printer housing when printing out of the desired data is completed when, for example, the operator wishes to print out only a desired portion or segment of the stored data on the printing medium. However, if the operator accidentally stops moving the printer housing before, or after, the printing of the desired data segment or portion is completed, the following drawbacks are incurred. If the operator stops moving the printer housing before the desired data printing is completed, a portion, or fragment, of the desired data segment to be printed may be incomplete. Alternatively, if the operator continues to move the printer housing after the desired data printer is completed, another portion of the data succeeding the above-described desired portion of data (i.e., desired data segment) may be additionally printed out on the printing medium. These effects are disadvantageous and lead to poor printing results.
In addition, it is practically difficult to manually move or sweep the printer housing over the printing medium at a constant sweeping speed. As a result, the resultant printing quality is lowered.
Under the above-described circumstances, using the above type of prior art device, a highly skilled sweeping technique is necessarily required for printer operators in order to obtain a satisfactory printing result. Moreover, a difficulty may exist in achieving the same printing conditions, i.e., the same printing quality and the same actual printed form, every time the same printer operator manually moves or sweeps the printer housing to print out the data stored in the memory unit.